Free point indicator apparatus



Sept. 17, 1968 L. K. MOORE Re. 26,458

FREE POINT INDICATOR APPARATUS Original Filed Oct 12, 1964 4Sheets-Sheet 1 law/ears K Moo/"e INVENTOR.

ATTOR/VEVJ' Sept. 17, 1968 L. K. MOORE 25,458

FREE POINT INDICATOR APPARATUS iriginal Filed Oct. 12, 1964 4Sheets-Sheet 2 L. K MOORE Sept. 17, 1968 FREE POINT INDICATOR APPARATUS4 Sheets-Sheet 3 LOW/ante ff Mao/e INVENTOR.

ATTOAIVEVJ Sept. 17, 1968 L. K MOORE FREE POINT INDICATOR APPARATUS 4Sheets-Sheet 4 C'riginal Filed Oct. 12, 1964 Lawrence Mao/6 INVENTOR.

ATTORA/EVJ United States Patent 26,458 FREE POINT INDICATOR APPARATUSLawrence K. Moore, 3716 Ingold St., Houston, Tex. 77005 Original No.3,331,243, dated July 18, 1967, Ser. No.

403,118, Oct. 12, 1964. Application for reissue Aug. 25, 1967, Ser. No.669,343

Claims. (Cl. 73-151) Matter enclosed in heavy brackets [1 appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

This invention relates to new and useful improvements in free pointindicator apparatus, and particularly a free point indicator apparatuswhich is lowered on and actuated by a non-electrical wire line.

In the drilling of wells, or in performing other well operations, thedrill pipe, tubing or casing may become stuck at some point in the well,making it necessary to locate the free point above the stuck point so asto perform any one of the usual techniques for the recovery of the pipe.In the past, electrical indicating devices have been used in attemptingto locate the stuck point and/ or free point in a pipe which is stuck ina well. Such devices are expensive due to the special electricalequipment involved. Furthermore, since such special electrical equipmentis used only for the free point indicator apparatus, it is not normallyavailable at a well site, and therefore, it must be brought to each jobwhen needed. The bulk of such equipment either necessitates the use ofspecial trucks for housing it, or the time-consuming task of setting upthe equipment at the well site must be undertaken.

It is an object of the present invention to provide a new and improvedfree point indicator apparatus for indicating the free point of a pipewhich is stuck in a well.

An important object of this invention is to provide a new and improvedfree point indicator apparatus which is adapted to be lowered on andactuated by a non-electrical flexible line.

Another object of this invention is to provide a new and improved freepoint indicator apparatus which is actuatable by a non-electrical wireline and which is capable of indicating longitudinal stretch and torquein a pipe so as to adequately inform the operator of the condition ofthe pipe at the free point.

A particular object of the present invention is to provide a new andimproved free point indicator apparatus wherein the location of the freepoint in a stuck pipe is determined by a mechanical means using atapered measuring or control rod in combination with one or morevariable opening mechanisms so as to obtain an indication of thecondition of the pipe when longitudinal stretch and/or torque forces areapplied to the stuck pipe.

The preferred embodiment of this invention will be describedhereinafter, together with other features thereof, and additionalobjects will become evident from such description.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown,and wherein:

FIG. 1 is a schematic view illustrating the apparatus of this inventionin its preferred form wherein both a stretch indicating means and atorque indicating means are provided in the same apparatus;

FIGS. 2A, 2B and 2C are views, partly in elevation and partly insection, illustrating the apparatus of this invention in one embodimentwherein only a stretch indicating means is provided;

Re. 26,458 Reissued Sept. 17, 1968 FIG. 3 is a view, partly in elevationand partly in section of a portion of the apparatus of FIG. 2B, butillustrating the apparatus in position for indicating a stretch in thepipe which is stuck in the well;

FIG. 4 is a horizontal cross-sectional view taken on line 44 of FIG. 3;

FIG. 5 is a horizontal sectional view taken on line 55 of FIG. 3;

FIG. 6 is an exploded view illustrating the preferred manner ofconstructing the sensing means of the apparatus of this invention;

FIG. 7 is a view, partly in elevation and partly in section,illustrating a portion of the apparatus of this invention for indicatingtorque developed in a stuck pipe;

FIG. 8 is a horizontal sectional view taken on line 8-8 of FIG. 7 andillustrating the torque unit with the sensing means in an open position;and

FIG. 9 is a view similar to FIG. 8, but illustrating the torque sensingmeans in the closed position.

In the drawings, the letter A designates generally the apparatus of thisinvention which is adapted to be positioned in a pipe P that has becomestuck in a well bore W at a keyseat K or other similar restriction.Briefly, the apparatus A is adapted to be lowered into the stuck pipe Pon a flexible non-electrical line L for the purpose of locating the freepoint of the pipe P. As will be explained more in detail hereinafter,the apparatus A is provided with means for indicating longitudinalstretch applied to the pipe P and is also capable of indicatingrotational torque applied to the pipe P. Such apparatus A is operated bythe wire line L so as to obtain such indications of longitudinalstretching and rotational torque by mechanical means.

Considering the invention more in detail, and referring in particular toFIGS. 2A through FIG. 6, one form of the apparatus A is adapted to beused for indicating only longitudinal stretch in the stuck pipe P. Suchapparatus has a tubular body B which has an upper body section and alower body section which are longitudinally movable relative to eachother within limits, The upper body section has upper friction means ordrag springs 10 mounted thereon. Such drag springs 10 are preferably ofthe bow type as illustrated in FIG. 2B and they are mounted so as tofrictionally engage the inner wall or surface of the stuck pipe P.Various types of friction means such as the drag springs 10 may beemployed. The springs 10 are of the resilient flexible metal type whichexert a frictional outward force and which have their lower ends securedagainst movement by screws 10a threaded into a sleeve 12. The upper endsof the drag springs 10 are free to move and are urged resilientlyoutwardly by a coil spring 11.

The tubular element or member 12 has a coupling 14 threadedly connectedthereto and to which a connector sleeve 15 is also attached by threadsor other suitable means. The connector sleeve 15 has one or morelaterally extending keys 15a formed thereon which fits into a slot orgroove 16a of a connecting sleeve 16. The key 15a is limited in itslongitudinal movement by the engagement with the lateral shoulder 16b inthe upward direction and by the engagement with another lateral shoulder17a on a connecting element 17 in the downward direction.

Thus, the upper body section shown in FIG. 2B includes the sleeve 12,the coupling member 14, and the connecting sleeve 15. The lower bodysection includes the connecting sleeve 16, the coupling element 17 andthe other tubular elements forming the body extending therebelow down tothe closure cap 18 at the lower end of the apparatus (FIG. 2C).

The lower body section carries a set of lower friction means or dragsprings 20 which are usually identical with the friction means or dragspring 10 and therefore are shown in FIG. 2C as identical with the dragsprings shown in FIG. 2B except that the drag springs are reversed.Thus, the upper ends of the drag springs 20 are secured to a lowersleeve 21 by attaching screws 20a or other suitable securing means,while the lower ends of the drag springs 20 are free to movelongitudinally on the element 21 and are resiliently urged upwardly by acoil spring 22. Therefore, the drag springs 20 maintain a constantoutward resilient frictional force on the inner surface or wall of thepipe P.

For sensing or detecting longitudinal stretch developed in the stuckpipe P, a sensing means or unit 25 is provided for coaction with acontrol rod 35, as will be explained. The sensing means 25 includes anannular actuating ring 26 which has an outwardly extending flange 26asecured between the end of a sleeve 27 and a shoulder on the sleeve 17to firmly secure such actuating ring 26 in a fixed position on the lowerbody section. The ring 26 also preferably has a tapered inner surface26b which serves as a guide surface as will be more evident hereinafter.

The sensing means 25 also includes a plurality of sensing dogs 28 whichare formed in two portions designated 29 and 30. As shown in detail inFIG. 6, each of the sensing elements or dogs 30 is formed with athreaded stud 30a which is adapted to extend through a flexiblerelatively soft rubber boot or sleeve 31. The hole in the sleeve or bootis designated 31a. A retainer nut 32 having internal threads 32a isadapted to be threaded on the stud 30a to form a fluid-tight seal and toalso provide a support for the sensing element 30 as it moves laterallywith respect to the longitudinal axis of the apparatus A. Thus, theretainer nut 32 fits within a recess 29a in the element 29 so as toprovide for the longitudinal movement of each element 30 with eachelement 29. The sensing elements 29 have inclined or I tapered surfaces29b which are in engagement with the inclined surface 26b of the ring26. In order to provide for the longitudinal movements of the elements30 and 29 to correspond proportionately with the inward and outwardlateral movements thereof, it is desirable to have the inclined surfaces26b and 29b formed at a forty-five degree angle as illustrated in FIG.28. Each of the wedgeshaped sensing elements 29 is also provided with agroove or recess 29c for receiving a pivoted link 33. Each of such links33 is pivotally connected to one of the elements 29 at 33a and is alsopivotally connected to the ring 26 at 33b (FIG. 213). Each link 33 ismovable within a slot 26c (FIG. 5) in the ring 26. Also, a secondactuating link 34 is provided for connection to each link 33, with apivotal connection therebetween being provided at 34a. The upper end ofeach link 34 is pivotally connected to the sleeve 15 at pivot 34b (FIG.2B).

With such construction, upon an upward movement of the upper bodysection, including the tubular sleeve 15 so as to move the shoulder 15aupwardly with respect to the shoulder 16b, the links 34 cause an upwardpivoting of the links 33 to slide the elements 29 upwardly with respectto the ring 26. Thus, the opening between the dogs or elements 30 isreduced to a smaller diameter, the purpose of which will be more evidenthereinafter.

It is to be noted that the boot 31 is made of a rubber which is flexibleand which has its upper end over a tube 14a and is held thereon by awire or other wrapping 31a. The lower end of the boot 31 is preferablyengaged on a sliding sleeve 36 which fits over a tube 37 and is sealedolf with an O-ring 36a. The upper end of the chamber 38 is sealed offwith an O-ring 16b. The lower end of the boot 31 is secured to thesliding sleeve 36 by a wire or other retaining element 31b. With theboot 31 in position as illustrated in FIG. 2B, a chamber 38 is providedwhich is sealed off from the well fluid in the pipe P. Such chamber 38may have oil or other lubricating liquid to facilitate the working ofthe elements 29 with respect to the ring 26 and also the movement of thesleeve 15 with respect to the sleeve 16. The boot 31 is especiallydesirable in cases where the apparatus A is used in deep drilling jobswhere mud and sand are present in the well and are circulated by thewell fluid. However, in some instances, the boot 31 may be omitted andalso the sensing plates or elements 30 may likewise be omitted.

The control rod has its upper portion formed with a uniform or constantexternal diameter as indicated at 35a, but the lower end is tapered asindicated at 35b (FIG. 2C) so as to provide a lower section of differentdiameters for a purpose to be described hereinafter. A lower stop nut35c is provided, preferably at the lower end of the control or measuringrod 35 for engagement with a stop ring 39 attached to a tubular element40 forming a part of the lower body section.

The upper end of the control or measuring rod 35 is preferably attachedto a conventional jar indicated at J in FIG. 2A. The upper end of therod 35 is shown in FIG. 2B as threaded to the lower jar housing 41,which housing 41 rests upon a latter shoulder 12a of the tubular bodysection 12. A plurality of weights X may be used above the jar J tofacilitate the lowering of the apparatus A into the pipe P, althoughboth the jars J and the weights X may be omitted in many uses of thepresent apparatus A. As illustrated in FIG. 2A, the weights X may bemoved upwardly relative to the jars I but such movement is limited by astop member 42 which has a stop flange 42a on its lower end engageablewith a lateral shoulder 41a. Upon a downward movement of the weights X,the lower surface 43 is adapted to contact the upper surface 41b toprovide a jarring downward movement in situations where that becomesdesirable or necessary for lowering the apparatus A in the pipe P. Whenthe weight of the apparatus A by itself is sufficient to accomplish thelowering thereof into the pipe P, the weights X and the jar I may beomitted, in which case the wire L is connected directly to the upper endof the measuring rod 35 by any conventional connector.

The indicatings at the top of the well which are obtained by theapparatus A are obtained on conventional equipment which includes aweight indicator and an odometer, as will be more evident hereinafter.The odometer is a conventional device for indicating the amount orfootage of the wire line L which has been lowered into the pipe P. Theodometer normally has a contact wheel (FIG. 1) which is moved by themovement of the wire line L, and such movements are shown on a dial ormeter 51. Thus, by looking at the meter 51, the operator can readilydetermine the amount of the wire line L which has been lowered into thepipe P, and normally this appears in feet on such meter 51.

A weight indicator 52 is also schematically illustrated in FIG. 1 sinceit likewise is preferably of conventional construction.

In the use of the apparatus illustrated in FIGS. 2A-6, only longitudinalstretch readings can be obtained. To obtain such longitudinal stretchreadings, the apparatus is usually first lowered into the pipe P to adepth at which it is believed the pipe P is free, although the firstreading may be taken in a stuck portion of the pipe P, if desired. Whenthe apparatus approaches a position in the pipe P for taking a reading,the weights X and jar J may be used to jar downwardly to be certain thatthe sleeve 15 is telescoped downwardly to the full extent within thesleeve 16 (FIG. 23), whereby the bore of the sensing element 25 is inthe fully opened position.

Then, the wire line L is raised upwardly until the full weight supportedby the wire line L is indicated at 52a on the weight indicator. Suchweight is known in advance by the operator. When the weight of the jarJ, the weights X, the control rod 35 and the other parts directlysupported by the wire line L is indicated at 5221 on the weightindicator 52, the operator knows that readings of increased weight onthe indicator 25 are indicative of strain on the line L. Therefore, theupward movement of the line is continued to move the lower stop 35c intoengagement with the stop 39, and an additional strain is taken on theline L which is indicated at 52b on the weight indicator 52. At thatpoint, the odometer 51 is read. Then, the wire line L is slacked off soas to allow the control or measuring rod 35 to move downwardly toposition the tapered portion 35b below the sensing mechanism or unit 25.Normally, it is only necessary to slack off on the wire line L about tenfeet in order to be certain that this condition exists. Then, alongitudinal pull is exerted on the pipe P at the surface in apredetermined amount. It is standard to apply about thirty-five thousandpounds pull on four and one-half inch pipe; other amounts of pull areused for other sizes of pipe.

While the pipe P is thus subjected to the longitudinal pull, the wireline L is again picked up until the weight indicator reads the sameamount as indicated at 52b. At that point, the odometer 51 is againread. If the pipe is free between the friction members and 20, thestretch in the pipe P will have caused the upper body section and thefriction means 10 to have moved upwardly relative to the lower bodysection and the lower friction means thereby causing the sleeve 15 tohave moved upwardly relative to the sleeve 16. Such stretch position isillustrated in FIG. 3, and there it can be seen that the sensingelements 29 and 30 have also moved inwardly to provide a reduceddiameter or opening as compared to the opened position of FIG. 2B. Byreason of such reduced opening or diameter, the tapered rod portion bcannot move for the full distance prior to the stretching of the pipeand therefore the upward travel of the rod 35 is stopped before the stopmember 35c engages the stop 39. Thus, when the apparatus A of the formshown in FIGS. 2A through 6 is in a free portion of the pipe P, theodometer 51 will show that a greater length of wire line L is suspendedin the well than on the first reading when the sensing means 25 wasopen. If, on the other hand, the apparatus A is entirely within thestuck portion of the pipe, the reading on the odometer 51 will show nochange from the first reading since the pipe P will not have beenstretched in the stuck portion and therefore the sensing means 25 willhave remained open even after the stretch or pull has been applied tothe pipe P, thereby allowing the rod 35 to move all the way to the upperend of its stroke with the stop member 35c in contact with the stop 39.In some instances, the pipe P is only partially stuck and therefore anintermediate reading or readings will be obtained.

Normally, in using the apparatus A, the apparatus is lowered so that itcan be checked in the free portion of the pipe for several readings toobtain an average reading and then the apparatus A is dropped downperhaps three hundred feet or more to be certain that the apparatus isthen in a stuck portion of the pipe. Then the apparatus can be raisedupwardly and successive readings may be taken until the free point ofthe pipe above the stuck point is located as accurately as possible.

In FIGS. 79, a torque sensing section or assembly is illustrated, whichmay be substituted for the stretch sensing mechanism or unit 25 of FIG.2B, or in some cases, the section shown in FIGS. 7-9 may be included asa part of the tool illustrated in FIGS. 2B and 2C.

When the torque section of FIGS. 7-9 is included with the apparatus A,the coupling section 55 (FIGS. 2B and 7) is threaded to a rotatablesleeve 56 rather than to the tubular section 40. Such coupling section56 is mounted for limited rotational movement within a connector sleeve57 which is in turn connected to threaded tubular sections 58, 59 and60. The element 60 corresponds in size and shape in the preferred formof the invention with the coupling element 55 so that it may beconnected to the tube 40, thereby joining the assembly of FIG. 7 to theassembly of FIG. 2C therebelow. The rod 35 is thus elongated to extendthrough the torque section shown in FIG. 7, thereby forming a part ofthe rod 35 shown in FIGS. 2B and 2C. In FIG. 23, a connector tube 61 isshown in dotted lines since such tube 61 is not used except when thetorque section of FIG. 7 is included as a part of the apparatus A. InFIG. 7, such tube 61 is shown in solid lines, and therefore theconnection between the portion shown in FIG. 2B and the portion shown inFIG. 7 can be readily seen. A flexible boot or tube 63 formed of rubberor other resilient material is disposed with its upper end stretchedover the tube 61 and held there by a wire wrapping or similar holdingmeans 63a. The lower end of the flexible tube 63 is secured to a slidingsleeve 64 by means of wire wrapping 63b or other similar securing means.The sliding sleeve 64 is similar to the sliding sleeve 36, and it isadapted to longitudinally slide on a tube 65 threaded or otherwiseconnected in the bore of the coupling 60 (FIG. 7). An O-ring seal 64a iscarried by the sliding sleeve 64.

A torque sensing unit 70 is provided in the torque section of FIGS. 7-9,and it includes the rotatable sleeve 56 which has one or more keys orstops 56a formed thereon for limited rotational movement within slots57a in the connector sleeve 57. Within the lower portion of the sleeve56 there are three sensing elements 71 which are adapted to be movedradially by coaction with a cam surface 56b.

When the boot 63 is employed, the sensing element 71 may have surfaceplates 72 disposed inwardly of the boot 63 and connected thereto in thesame manner as illustrated in connection with FIG. 6 of the drawings sothat the inner dogs or elements 72 move together with the elements 71and in reality are a part thereof when the boot 63 is employed. When theboot 63 is omitted, the elements 72 may be likewise omitted.

The elements 71 are guided for radial movement by pins 73 whichpreferably have a square cross section and which fit into slots 71a. Thedogs 71 are moved inwardly by coaction with the cam surfaces 56b as suchcam surfaces 56b move counterclockwise from the position shown in FIG. 8to the position shown in FIG. 9.

Although not essential, it is desirable to provide a spring 75 which hasits upper end 75a secured to the sleeve 56 and its lower end 75b securedto the sleeve 57 for exerting a rotational force on the sleeve 56 tomaintain the dogs 71 and the elements 72 therewith in the closedposition of FIG. 9 except when taking a reading, as will be explained.

Considering now the operation of the torque section of the apparatus Aand assuming that it is mounted in the tool as heretofore described andas schematically illustrated in FIG. 1, the apparatus A is firstdisposed in the pipe P prior to taking any stretch or applying anyrotational or torque to the pipe P. The wire line L is pulled upwardlyuntil the indicator 52 again indicates the total weight suspended by thewire line L such as indicated at 52a. The line L is thereafter movedupwardly after the weight is indicated at 52a until an additional amountof strain or weight is indicated on the weight indicator 52 such as at52b. Since the torque sensing elements 71 and 72 are in their closedposition, the additional weight will be indicated at 52b almostimmediately upon the entry of the tapered section 35b into the bore ofthe sensing unit 70. Therefore, as soon as such additional weight isindicated, the lifting with the line L is stopped and a reading on theodometer 51 is taken.

The line L is then slacked off only enough to relieve the strain andreturn the weight indicator reading to 52a. A rotational or torque forceis then applied to the pipe P at the surface of the well in a prescribedamount, which normally would be about one round per one thousand feet ofestimated free pipe. Such rotation or torque force is applied in aclockwise direction as viewed from the top of the well and as seen inFIGS. 8 and 9. The twisting of the pipe P imparts a turning movement tothe free portion of the pipe P and therefore so long as the upper dragsprings 10 are in a free portion of the pipe, there will be a relativemovement of the upper drag springs with respect to the lower dragsprings 20. Such relative movement causes a corresponding clockwisemovement (as viewed in FIG. 9) of the sleeve or tube 56 so as to allowthe elements 71 to open to provide a larger bore within the sensingmeans 70. It is to be noted that the cam surface 56b is at such an anglein the preferred form of the invention to provide for the same unit ofradial movement outwardly for the elements 71 for each unit of rotationof the sleeve 56. Such cam surface 56b will therefore approximate aforty-five degree angle, but allowance must be made for the rotationalmovement of the sleeve 56 relative to the elements 71. Thus, assumingthat a change in rotational movement of the sleeve 56 is one hundredthof an inch, likewise the diameter of the bore between the elements 72would change by one hundredth of an inch, and such unit change is thesame for each unit of rotation of the element 56 in the preferred formof the invention. In that way, the extent of the opening of the bore ofthe sensing element 70 will correspond with the amount of torque in thepipe P and such amount will be reflected by the length of the taperedportion 35b of the control rod 35 which is able to move into such boreof the sensing means 70 as will be more evident.

Thus, with the sensing element 70 in a partially opened position, oreven a fully opened position, by reason of the torque force, put intothe pipe P, such rotational torque can be determined by again raisingthe wire line L until the weight indicator again reads the amountindicated at 52b. If the apparatus A is in a free portion of the pipe P,or at least the upper drag springs 10 are in such free portion, theelements or dogs 71 and 72 will be open to some extent as compared tothe closed position of FIG. 9 and therefore the odometer will read alesser amount than when the dogs 71 and 72 were in the closed positionof FIG. 9. The extent of the opening will be indicated by such readingon the odometer 51.

If both of the springs 10 and are in the stuck portion of the pipe P,then upon pulling upwardly on the wire line L and picking up on suchline L until the load is the same as previously indicated at 52b on theweight indicator 52, the operator will know that the apparatus A is inthe stuck portion of the pipe because no change will occur in theodometer reading. By selecting intermediate readings between the stuekpipe readings and the free pipe readings, the free point of the pipe maybe located as closely as possible.

When the torque section of FIGS. 7-9 is incorporated as a part of theapparatus A as indicated in FIG. 1, the torque reading may be obtainedfirst as pointed out above and then when it is desired to take a stretchreading, the torque section may be completely opened so that it will notinterfere with the taking of the stretch reading. The opening of thetorque section is accomplished by pulling upwardly on the wire line Luntil the full taper of the tapered portion b has moved upwardly and thestop nut 35c has contacted the stop 39. In such case, the dogs 71 and 72are moved outwardly to the position shown in FIG. 8 and during suchmovement, the spring 75 is stressed so that relative movement of thesleeves 56 and 57 is obtained. The upper drag springs 10 are turnedclockwise (as viewed in FIG. 9) and/or the drag springs 20 are turnedcounterclockwise providing some longi tudinal movement of the entireapparatus is also obtained to relieve the frictional engagement of thesprings 10 and 20 in the pipe P. The dogs 71 and 72 are held in suchoutward position by the friction of the springs 10 and 20 after suchlongitudinal movement of the entire tool is stopped. The operator at thesurface of the well can tell that such condition has been obtained bythe amount of travel of the line L as shown on the odometer 51 with thefull weight of the apparatus supported on the wire line L. Normally. asthe tapered surface 35b first engages the dogs 72, the full weight ofthe apparatus is supported on the line L, but as the dogs 71 and 72start Iii] to open, then the weight on the line L drops since only thecontrol rod 35, the weights X, the jar J and the parts directly on theline L are then supported thereby. When the stop nut 35c engages thestop 39, the full weight of the apparatus will again be on the wire lineL and if the odometer reading indicates that the line L has movedupwardly a sufficient distance to enable the stop nut 35c to havereached the stop 39, the operator knows the dogs 71 and 72 are fullyopen. After the torque section is in such maximum opened position, theWire line L may be lowered and the torque section 70 will stay in suchopened position. Then, the stretch section can be used by taking astretch in the pipe P as previously explained, followed by a lifting ofthe wire line L to again assume the load indicated at 52b and by takinga measurement to indicate the extent to which the tapered portion 35bhas passed into the bore of the sensing means 25.

The stretch reading may be taken first by following the procedure ofopening the torque means 70 if desired since the torque means 70actually does not interfere with the taking of the stretch readings onceit has been fully opened. To return the torque sensing means 72 to itsclosed position for performing the torque test, a simple jar or downwardmovement of the apparatus A will be sufficient to release the frictionalforce exerted by the drag springs 10 and will allow the tension spring75 to return the torque sensing means 72 to the closed position of FIG.9. Once the torque sensing means is in the position shown in FIG. .9 thesteps described above for obtaining a reading on the torque sensingmeans 70 may be followed.

lt should be pointed out that the tool of this invention as disclosedherein may be operated upside down in which case the readings on theodometer 51 will be taken by slacking off on the wire line rather thanwhen pulling on such wire line L. It is therefore to be understood thatthe use of the apparatus A in an upside down position with the wire lineL connected to the lower end of the control rod 35 is within the scopeof this invention.

The foregoing disclosure and description of the inventin is illustrativeand explanatory thereof and various changes in the size, shape andmaterials, as well as in the details of the illustrated construction,may be made within the scope of the appended claims without departingfrom the spirit of the invention.

What is claimed is:

1. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck P 1 (c) said body having an upper bodysection and a lower body section with means for permitting limitedrelative longitudinal movement therebetween,

(.d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) sensing means operable in response to longitudinal movement of afree or partially free portion of the stuck pipe, and

(g) a control rod operably connected to the flexible non-electrical linefor controlling the amount of movement of said line different distancesdepending upon the amount of movement in the pipe by coaction of thecontrol rod with said sensing means to thereby obtain an indication onthe amount of movement of the free or partially free portion of thestuck pipe.

2. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

1b) a flexible non-electrical line connected to said lubular body forlowering the body into the stuck pipe,

(c) said body having an upper body section and a lower body section withmeans for permitting limited relative longitudinal movementtherebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) a variable bore sensing means operable to vary the size of the borein response to longitudinal movement of a free or partially free portionof the stuck pipe, and

(g) a control rod longitudinally movable in the bore of the sensingmeans for different distances depending upon the size of the variablebore to thereby indicate variations in the longitudinal movement of thefree portion of the pipe.

3. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck pipe,

(c) said body having an upper body section and a lower body section withmeans for permitting limited relative longitudinal movementtherebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) a variable bore sensing means operable to vary the size of the borein response to longitudinal stretching of the stuck pipe, and

(g) a control rod having sections of different diameters andlongitudinally movable in the bore of the sensing means until thediameter of the control rod within the bore of sensing means correspondswith the diameter of the bore to thereby indicate the amount of stretchin the stuck pipe.

4. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck pipe,

(c) said body having an upper body section and a lower body section withmeans for permitting limited relative longitudinal movementtherebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) a variable bore sensing means operable to vary the size of the borein response to longitudinal stretching of the stuck pipe, and

(g) a control rod having a tapered section and longitudinally movable inthe bore of the sensing means to position same in contact with such borefor indicating the stretch in the stuck pipe by the amount of movementof the control rod before it reaches such contact.

5. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck pipe,

(c) said body having an upper body section and a lower body section withmeans for permitting limited relative longitudinal movementtherebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) sensing means having a variable sized opening which is operable tovary the size of such opening in response to longitudinal movement ofthe upper and lower body sections relative to each other, and

(g) a control rod extending through said opening of the sensing meansand operably connected to said flexible non-electrical line for movementrelative to said sensing means different distances depending upon thesize of the variable opening in said sensing means for therebyindicating whether the apparatus is in a free or partially free portionof the stuck pipe.

6. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck pipe,

(c) said body having an upper body section and a lower body section withmeans for permitting the limited relative [longitudinal] rotationalmovement therebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) sensing means having a variable sized opening which is operable tovary the size of such opening in response to torque forces developed inthe stuck pipe between the upper and lower friction means, and

(g) a control rod extending through said opening of the sensing meansand operably connected to said flexible non-electrical line for movementrelative to said sensing means different distances depending upon thesize of the variable opening in said sensing means for therebyindicating whether the apparatus is in a free or partially free portionof the stuck pipe.

7. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck pipe,

(0) said body having an upper body section and a lower body section withmeans for permitting limited relative [longitudinal] rotational movementtherebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) sensing means having a variable sized opening which is operable tovary the size of such opening in response to rotational movement of theupper and lower body sections relative to each other, and

(g) a control rod extending through said opening of the sensing meansand operably connected to said flexible non-electrical line for movementrelative to said sensing means diflerent distances depending upon thesize of the variable opening in said sensing means for therebyindicating whether the apparatus is in a free or partially free portionof the stuck pipe.

8. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck P p (c) said body having an upper bodysection and a lower body section with means for permitting limitedrelative [longitudinal] rotational movement therebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) a variable bore sensing means operable to vary the size of the borein response to torque developed in the pipe between the upper and lowerfriction means, and

(g) a control rod longitudinally movable in the bore of the sensingmean-s for different distances depend- 1 1 ing upon the size of thevariable bore to thereby indicate variations in the torque developed inthe pipe between the upper and lower friction means.

9. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck p p (c) said body having an upper bodysection and a lower body section with means for permitting limitedrelative [longitudinal] rotational movement therebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) a variable bore sensing means operable to vary the size of the borein response to torque developed in the pipe between the upper and lowerfriction means, and

(g) a control rod having sections of different diameters andlongitudinally movable in the bore of the sensing means until thediameter of the control rod within the bore of the sensing meanscorresponds with the diameter of the bore to thereby indicate the amountof torque developed in the pipe between the upper and lower frictionmeans.

10. Free point indicator apparatus, comprising:

(a) a tubular body adapted to be lowered into the bore of a pipe whichis stuck in a well,

Cit

(b) a flexible non-electrical line connected to said tubular body forlowering the body into the stuck p p (c) said body having an upper bodysection and a lower body section with means for permitting limitedrelative [longitudinal] rotational movement therebetween,

(d) an upper friction means on said upper body section for frictionallyengaging the stuck pipe,

(e) a lower friction means on said lower body section for frictionallyengaging the stuck pipe,

(f) a variable bore sensing means operable to vary the size of the borein response to torque developed in the pipe between the upper and lowerfriction means, and

(g) a control rod having a tapered section and longitudinally movable inthe bore of the sensing means to position same in contact with such borefor indicating the torque developed in the pipe between the upper andlower friction means.

of record in the patented file of this patent or the original 25 patent.

UNITED STATES PATENTS 2/1944 Mestas. 7/1963 Rogers 73-151 RICHARD c.QUEISSER, Primary Examiner.

J. W. MYRACLE, Assistant Examiner.

